Mechanism and force-energy parameters of a hollow shaft’s multi-wedge synchrostep cross-wedge rolling

다국어 초록 (Multilingual Abstract)

First, the rotation condition of a hollow shaft’s multi-wedge synchrostep cross-wedge rolling (MSCWR) is determined and the relevant influencing rule is illustrated based on a mechanical model of the hollow shaft and the theory of solid shaft’s rotation condition. The influence rule states that the increasing number of wedges increases the shrinkage rate of the hollow shaft and diminishes the rotation conditions, which can be improved by increasing μ on the forming surface of the hollow rolling mold, setting the stretching b , and forming α angles at approximately 4°-12° and 15°-35°, respectively. Second, a rigid-plastic finite element model is established for the hollow shaft with MSCWR by using the DEFORM-3D software, and the deformation mechanism of the hollow shaft is illustrated. The deformation degree of the rolling piece at the stretching stage decreases gradually from the surface to the interior of the hollow shaft, and radial compressive and transverse tensile strains interact with each other, thus resulting in an elliptic cross section of the hollow shaft.
Stress field is mainly distributed in the exterior margin and then permeates into the inner part along the direction of the wall thickness, gradually transforming from compressive stress into tensile stress. Third, the influence of mechanical parameters on hollow shaft rolling is analyzed. The increased stretching angle increases the radial force, transverse force, and rolling torque and decreases the axial force.
Moreover, the enlarged forming angle reduces the radial and transverse forces, while the decreased rolling torque increases the axial force. Finally, the 1:5 MSCWR experiment on the hollow shaft verifies the proposed finite element model’s accuracy. Results of the research provide a theoretical basis for the MSCWR of a precise hollow shaft.

참고문헌 (Reference)

1 H. Ding, "Thermo mechanical coupled numerical simulation on cross wedge rolling of hollow shaft parts with equal inner diameters" 32 (32): 25-529, 2010

2 X. D. Shu, "Theoretical and experimental study of varying rule of rolling-moment about crosswedge rolling" 187-188, 2007

3 X. D. Shu, "The research on the process parameters impact on the forming mechanism multi-wedge cross wedge rolling" 7 (7): 222-226, 2005

4 C. M. Li, "The research and the actuality on methods of forming railway shaft" 6 : 5-8, 2006

5 J. Bartnicki, "The aspects of stability in crosswedge rolling processes of hollowed shafts" 155-156, 2004

6 X. D. Shu, "The Theory and Application on Multi-wedge Synchronous Cross Wedge Rolling" Science Press 2-, 2011

7 W. Ding, "Study on the ovality of hollow shafts with equal inner diameter formed by cross wedge rolling" 17 (17): 27-31, 2010

8 Z. Pater, "Study of the process stability of cross wedge rolling" 458-462, 1999

9 H. C. Ji, "Research on Cross Wedge Rolling Forming and Microstructure Evolution of 21-4N for Hollow Valve" University of Science and Technology Beijing 2017

10 W. Peng, "Multi-wedge cross wedge rolling process of 42CrMo4 large and long hollow shaft" 45 (45): 836-842, 2016

11 J. Zhao, "Influence rules of technological parameters on interface quality of multi-wedge cross wedge rolling work piece" 44 (44): 209-214, 2008

12 C. P. Yang, "Influence of the flattening deformation on the forming of hollow parts in cross wedge rolling" 34 (34): 881-885, 2014

13 J. C. Liang, "Influence of technological parameters about cross rolling hollow part rolling work piece wall thickness change" 27 (27): 108-, 1996

14 P. H. Yu, "Influence of process parameters on grain size of hollow shafts in multi-wedge cross wedge rolling" 43 (43): 96-99, 2014

15 X. D. Shu, "Influence of mold technological parameters on the forming force parameters in multiwedge rolling of the railway hollow shafts" 23 (23): 23-28, 2016

16 Z. Pater, "Finished cross wedge rolling of hollowed cutters" 51 (51): 205-, 2006

17 S. Urankar, "Establishment of failure conditions for the cross wedge rolling of hollow shafts" 177 : 545-549, 2006

18 S. Urankar, "Development of a critical friction model for cross wedge rolling hollow shafts" 177 : 539-544, 2006

19 X. D. Shu, "Cross Wedge Rolling Theory and Forming Technology" Science Press 1-10, 2014

20 J. Zhao, "Analysis of influence factors on mechanical parameters in multi-wedge cross rolling wedge forming automobile semi-axes" 29 (29): 63-66, 2007